docs: def pivot(self, binned=False):
          """Calculate :ref:`pysynphot-formula-pivwv`.
  
          Parameters
          ----------
          binned : bool
              This is reserved for use by `~pysynphot.observation.Observation`.
              If `True`, binned wavelength set is used. Default is `False`.
  
          Returns
          -------
          ans : float
              Pivot wavelength.
  
          Raises
          ------
          AttributeError
              Binned wavelength set requested but not found.
  
          """
          if binned:
              try:
                  wave = self.binwave
              except AttributeError:
                  raise AttributeError('Class ' + str(type(self)) +
                                       ' does not support binning.')
          else:
              wave = self.wave
  
          countmulwave = self(wave)*wave
          countdivwave = self(wave)/wave
  
          num = self.trapezoidIntegration(wave, countmulwave)
          den = self.trapezoidIntegration(wave, countdivwave)
  
          if num == 0.0 or den == 0.0:
              return 0.0
  
          return math.sqrt(num/den)